Show navigation bar on external displays

Add phone navigation bar in 2 situations:
1. When status bar is created and external
   displays,which supports system decorations exist.
2. When new displays are added and the displays supports system
   decorations

TODO: 1. Support nav bar logic in WM code.
      2. Add lightController and more for external nav bars
      3. Move the logic to DisplayNavigationController

Bug: 115978725
Test: Manual
Test: atest SystemUITests
Test: atest ActivityManagerMultiDisplayTests
Test: atest ActivityManagerMultiDisplayTests#testNavBarShowingOnDisplayWithDecor
Test: atest ActivityManagerMultiDisplayTests#testNavBarNotShowingOnDisplayWithoutDecor
Test: atest ActivityManagerMultiDisplayTests#testNavBarNotShowingOnPrivateDisplay
Change-Id: Ibf7c548d911ec2aca213b5ac0ecbd67f5f9fbeb5